Merge branch 'tracing/ftrace' into tracing/core

1 files changed, 333 insertions, 35 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index bdaf60d3d337..5db7485158df 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1684,23 +1684,20 @@ static struct seq_operations tracer_seq_ops = {
 };
 
 static struct trace_iterator *
-__tracing_open(struct inode *inode, struct file *file, int *ret)
+__tracing_open(struct inode *inode, struct file *file)
 {
         long cpu_file = (long) inode->i_private;
+        void *fail_ret = ERR_PTR(-ENOMEM);
         struct trace_iterator *iter;
         struct seq_file *m;
-        int cpu;
+        int cpu, ret;
 
-        if (tracing_disabled) {
-                *ret = -ENODEV;
-                return NULL;
-        }
+        if (tracing_disabled)
+                return ERR_PTR(-ENODEV);
 
         iter = kzalloc(sizeof(*iter), GFP_KERNEL);
-        if (!iter) {
-                *ret = -ENOMEM;
-                goto out;
-        }
+        if (!iter)
+                return ERR_PTR(-ENOMEM);
 
         /*
          * We make a copy of the current tracer to avoid concurrent
@@ -1708,10 +1705,9 @@ __tracing_open(struct inode *inode, struct file *file, int *ret)
          */
         mutex_lock(&trace_types_lock);
         iter->trace = kzalloc(sizeof(*iter->trace), GFP_KERNEL);
-        if (!iter->trace) {
-                *ret = -ENOMEM;
+        if (!iter->trace)
                 goto fail;
-        }
+
         if (current_trace)
                 *iter->trace = *current_trace;
 
@@ -1750,9 +1746,11 @@ __tracing_open(struct inode *inode, struct file *file, int *ret)
         }
 
         /* TODO stop tracer */
-        *ret = seq_open(file, &tracer_seq_ops);
-        if (*ret)
+        ret = seq_open(file, &tracer_seq_ops);
+        if (ret < 0) {
+                fail_ret = ERR_PTR(ret);
                 goto fail_buffer;
+        }
 
         m = file->private_data;
         m->private = iter;
@@ -1762,7 +1760,6 @@ __tracing_open(struct inode *inode, struct file *file, int *ret)
 
         mutex_unlock(&trace_types_lock);
 
- out:
         return iter;
 
  fail_buffer:
@@ -1775,7 +1772,7 @@ __tracing_open(struct inode *inode, struct file *file, int *ret)
         kfree(iter->trace);
         kfree(iter);
 
-        return ERR_PTR(-ENOMEM);
+        return fail_ret;
 }
 
 int tracing_open_generic(struct inode *inode, struct file *filp)
@@ -1815,9 +1812,12 @@ static int tracing_release(struct inode *inode, struct file *file)
 
 static int tracing_open(struct inode *inode, struct file *file)
 {
-        int ret;
+        struct trace_iterator *iter;
+        int ret = 0;
 
-        __tracing_open(inode, file, &ret);
+        iter = __tracing_open(inode, file);
+        if (IS_ERR(iter))
+                ret = PTR_ERR(iter);
 
         return ret;
 }
@@ -1825,11 +1825,13 @@ static int tracing_open(struct inode *inode, struct file *file)
 static int tracing_lt_open(struct inode *inode, struct file *file)
 {
         struct trace_iterator *iter;
-        int ret;
+        int ret = 0;
 
-        iter = __tracing_open(inode, file, &ret);
+        iter = __tracing_open(inode, file);
 
-        if (!ret)
+        if (IS_ERR(iter))
+                ret = PTR_ERR(iter);
+        else
                 iter->iter_flags |= TRACE_FILE_LAT_FMT;
 
         return ret;
@@ -2024,57 +2026,62 @@ static ssize_t
 tracing_trace_options_read(struct file *filp, char __user *ubuf,
                        size_t cnt, loff_t *ppos)
 {
-        int i;
+        struct tracer_opt *trace_opts;
+        u32 tracer_flags;
+        int len = 0;
         char *buf;
         int r = 0;
-        int len = 0;
-        u32 tracer_flags = current_trace->flags->val;
-        struct tracer_opt *trace_opts = current_trace->flags->opts;
+        int i;
 
 
         /* calculate max size */
         for (i = 0; trace_options[i]; i++) {
                 len += strlen(trace_options[i]);
-                len += 3; /* "no" and space */
+                len += 3; /* "no" and newline */
         }
 
+        mutex_lock(&trace_types_lock);
+        tracer_flags = current_trace->flags->val;
+        trace_opts = current_trace->flags->opts;
+
         /*
          * Increase the size with names of options specific
          * of the current tracer.
          */
         for (i = 0; trace_opts[i].name; i++) {
                 len += strlen(trace_opts[i].name);
-                len += 3; /* "no" and space */
+                len += 3; /* "no" and newline */
         }
 
         /* +2 for \n and \0 */
         buf = kmalloc(len + 2, GFP_KERNEL);
-        if (!buf)
+        if (!buf) {
+                mutex_unlock(&trace_types_lock);
                 return -ENOMEM;
+        }
 
         for (i = 0; trace_options[i]; i++) {
                 if (trace_flags & (1 << i))
-                        r += sprintf(buf + r, "%s ", trace_options[i]);
+                        r += sprintf(buf + r, "%s\n", trace_options[i]);
                 else
-                        r += sprintf(buf + r, "no%s ", trace_options[i]);
+                        r += sprintf(buf + r, "no%s\n", trace_options[i]);
         }
 
         for (i = 0; trace_opts[i].name; i++) {
                 if (tracer_flags & trace_opts[i].bit)
-                        r += sprintf(buf + r, "%s ",
+                        r += sprintf(buf + r, "%s\n",
                                 trace_opts[i].name);
                 else
-                        r += sprintf(buf + r, "no%s ",
+                        r += sprintf(buf + r, "no%s\n",
                                 trace_opts[i].name);
         }
+        mutex_unlock(&trace_types_lock);
 
-        r += sprintf(buf + r, "\n");
         WARN_ON(r >= len + 2);
 
         r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
 
         kfree(buf);
-
         return r;
 }
 
@@ -2149,7 +2156,9 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf,
 
         /* If no option could be set, test the specific tracer options */
         if (!trace_options[i]) {
+                mutex_lock(&trace_types_lock);
                 ret = set_tracer_option(current_trace, cmp, neg);
+                mutex_unlock(&trace_types_lock);
                 if (ret)
                         return ret;
         }
@@ -2275,8 +2284,17 @@ int tracer_init(struct tracer *t, struct trace_array *tr)
         return t->init(tr);
 }
 
+struct trace_option_dentry;
+
+static struct trace_option_dentry *
+create_trace_option_files(struct tracer *tracer);
+
+static void
+destroy_trace_option_files(struct trace_option_dentry *topts);
+
 static int tracing_set_tracer(const char *buf)
 {
+        static struct trace_option_dentry *topts;
         struct trace_array *tr = &global_trace;
         struct tracer *t;
         int ret = 0;
@@ -2297,7 +2315,12 @@ static int tracing_set_tracer(const char *buf)
         if (current_trace && current_trace->reset)
                 current_trace->reset(tr);
 
+        destroy_trace_option_files(topts);
+
         current_trace = t;
+
+        topts = create_trace_option_files(current_trace);
+
         if (t->init) {
                 ret = tracer_init(t, tr);
                 if (ret)
@@ -3093,6 +3116,279 @@ static void tracing_init_debugfs_percpu(long cpu)
 #include "trace_selftest.c"
 #endif
 
+struct trace_option_dentry {
+        struct tracer_opt               *opt;
+        struct tracer_flags             *flags;
+        struct dentry                   *entry;
+};
+
+static ssize_t
+trace_options_read(struct file *filp, char __user *ubuf, size_t cnt,
+                        loff_t *ppos)
+{
+        struct trace_option_dentry *topt = filp->private_data;
+        char *buf;
+
+        if (topt->flags->val & topt->opt->bit)
+                buf = "1\n";
+        else
+                buf = "0\n";
+
+        return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
+}
+
+static ssize_t
+trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt,
+                         loff_t *ppos)
+{
+        struct trace_option_dentry *topt = filp->private_data;
+        unsigned long val;
+        char buf[64];
+        int ret;
+
+        if (cnt >= sizeof(buf))
+                return -EINVAL;
+
+        if (copy_from_user(&buf, ubuf, cnt))
+                return -EFAULT;
+
+        buf[cnt] = 0;
+
+        ret = strict_strtoul(buf, 10, &val);
+        if (ret < 0)
+                return ret;
+
+        ret = 0;
+        switch (val) {
+        case 0:
+                /* do nothing if already cleared */
+                if (!(topt->flags->val & topt->opt->bit))
+                        break;
+
+                mutex_lock(&trace_types_lock);
+                if (current_trace->set_flag)
+                        ret = current_trace->set_flag(topt->flags->val,
+                                                      topt->opt->bit, 0);
+                mutex_unlock(&trace_types_lock);
+                if (ret)
+                        return ret;
+                topt->flags->val &= ~topt->opt->bit;
+                break;
+        case 1:
+                /* do nothing if already set */
+                if (topt->flags->val & topt->opt->bit)
+                        break;
+
+                mutex_lock(&trace_types_lock);
+                if (current_trace->set_flag)
+                        ret = current_trace->set_flag(topt->flags->val,
+                                                      topt->opt->bit, 1);
+                mutex_unlock(&trace_types_lock);
+                if (ret)
+                        return ret;
+                topt->flags->val |= topt->opt->bit;
+                break;
+
+        default:
+                return -EINVAL;
+        }
+
+        *ppos += cnt;
+
+        return cnt;
+}
+
+
+static const struct file_operations trace_options_fops = {
+        .open = tracing_open_generic,
+        .read = trace_options_read,
+        .write = trace_options_write,
+};
+
+static ssize_t
+trace_options_core_read(struct file *filp, char __user *ubuf, size_t cnt,
+                        loff_t *ppos)
+{
+        long index = (long)filp->private_data;
+        char *buf;
+
+        if (trace_flags & (1 << index))
+                buf = "1\n";
+        else
+                buf = "0\n";
+
+        return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
+}
+
+static ssize_t
+trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt,
+                         loff_t *ppos)
+{
+        long index = (long)filp->private_data;
+        char buf[64];
+        unsigned long val;
+        int ret;
+
+        if (cnt >= sizeof(buf))
+                return -EINVAL;
+
+        if (copy_from_user(&buf, ubuf, cnt))
+                return -EFAULT;
+
+        buf[cnt] = 0;
+
+        ret = strict_strtoul(buf, 10, &val);
+        if (ret < 0)
+                return ret;
+
+        switch (val) {
+        case 0:
+                trace_flags &= ~(1 << index);
+                break;
+        case 1:
+                trace_flags |= 1 << index;
+                break;
+
+        default:
+                return -EINVAL;
+        }
+
+        *ppos += cnt;
+
+        return cnt;
+}
+
+static const struct file_operations trace_options_core_fops = {
+        .open = tracing_open_generic,
+        .read = trace_options_core_read,
+        .write = trace_options_core_write,
+};
+
+static struct dentry *trace_options_init_dentry(void)
+{
+        struct dentry *d_tracer;
+        static struct dentry *t_options;
+
+        if (t_options)
+                return t_options;
+
+        d_tracer = tracing_init_dentry();
+        if (!d_tracer)
+                return NULL;
+
+        t_options = debugfs_create_dir("options", d_tracer);
+        if (!t_options) {
+                pr_warning("Could not create debugfs directory 'options'\n");
+                return NULL;
+        }
+
+        return t_options;
+}
+
+static void
+create_trace_option_file(struct trace_option_dentry *topt,
+                         struct tracer_flags *flags,
+                         struct tracer_opt *opt)
+{
+        struct dentry *t_options;
+        struct dentry *entry;
+
+        t_options = trace_options_init_dentry();
+        if (!t_options)
+                return;
+
+        topt->flags = flags;
+        topt->opt = opt;
+
+        entry = debugfs_create_file(opt->name, 0644, t_options, topt,
+                                    &trace_options_fops);
+
+        topt->entry = entry;
+
+}
+
+static struct trace_option_dentry *
+create_trace_option_files(struct tracer *tracer)
+{
+        struct trace_option_dentry *topts;
+        struct tracer_flags *flags;
+        struct tracer_opt *opts;
+        int cnt;
+
+        if (!tracer)
+                return NULL;
+
+        flags = tracer->flags;
+
+        if (!flags || !flags->opts)
+                return NULL;
+
+        opts = flags->opts;
+
+        for (cnt = 0; opts[cnt].name; cnt++)
+                ;
+
+        topts = kzalloc(sizeof(*topts) * (cnt + 1), GFP_KERNEL);
+        if (!topts)
+                return NULL;
+
+        for (cnt = 0; opts[cnt].name; cnt++)
+                create_trace_option_file(&topts[cnt], flags,
+                                         &opts[cnt]);
+
+        return topts;
+}
+
+static void
+destroy_trace_option_files(struct trace_option_dentry *topts)
+{
+        int cnt;
+
+        if (!topts)
+                return;
+
+        for (cnt = 0; topts[cnt].opt; cnt++) {
+                if (topts[cnt].entry)
+                        debugfs_remove(topts[cnt].entry);
+        }
+
+        kfree(topts);
+}
+
+static struct dentry *
+create_trace_option_core_file(const char *option, long index)
+{
+        struct dentry *t_options;
+        struct dentry *entry;
+
+        t_options = trace_options_init_dentry();
+        if (!t_options)
+                return NULL;
+
+        entry = debugfs_create_file(option, 0644, t_options, (void *)index,
+                                    &trace_options_core_fops);
+
+        return entry;
+}
+
+static __init void create_trace_options_dir(void)
+{
+        struct dentry *t_options;
+        struct dentry *entry;
+        int i;
+
+        t_options = trace_options_init_dentry();
+        if (!t_options)
+                return;
+
+        for (i = 0; trace_options[i]; i++) {
+                entry = create_trace_option_core_file(trace_options[i], i);
+                if (!entry)
+                        pr_warning("Could not create debugfs %s entry\n",
+                                   trace_options[i]);
+        }
+}
+
 static __init int tracer_init_debugfs(void)
 {
         struct dentry *d_tracer;
@@ -3111,6 +3407,8 @@ static __init int tracer_init_debugfs(void)
         if (!entry)
                 pr_warning("Could not create debugfs 'trace_options' entry\n");
 
+        create_trace_options_dir();
+
         entry = debugfs_create_file("tracing_cpumask", 0644, d_tracer,
                                     NULL, &tracing_cpumask_fops);
         if (!entry)